In recent years, a feed system (a non-contact feed system, or a wireless charging system) performing non-contact power supply (power transmission) on consumer electronics devices (CE devices) such as mobile phones and portable music players has attracted attention. Accordingly, charging is allowed to be started by not inserting (connecting) a connector of a power supply such as an AC adapter into a unit but placing an electronic apparatus (a secondary-side unit) on a charging tray (a primary-side unit). In other words, terminal connection between the electronic apparatus and the charging tray is unnecessary.
As a method of performing non-contact power supply in such a way, an electromagnetic induction method is well known. In addition, a non-contact feed system using a method called magnetic resonance method which uses electromagnetic resonance phenomenon has attracted attention. Such a non-contact feed system has been disclosed in, for example, PTLs 1 to 6.